西太湖湖滨典型河网区与太湖水量的交换

以西太湖湖滨典型河网区——宜兴大浦河网区为研究区域,对于该典型河网区与太湖之间的水量交换情况进行了系统的计算研究．考虑降雨因素的影响,采用考虑下垫面分类的产汇流模型,对各计算年内(2002年(基准年)．1998年(丰水年),1995年(平水年),1994年(枯水年))典型河网区及其西部山地区域的降雨径流过程进行了产汇流模拟．建立起适合该河网区域的非稳态河网水量模型,结合径流计算结果,对各年内典型河网区内水流的动态变化进行了计算模拟,对典型河网区与太湖水体的水量交换情况进行系统研究,分别对顺流与逆流情况下交换水量的年内分布与年际变化规律进行了分析．     

青藏高原东北侧臭氧垂直分布与平流层-对流层物质交换

利用臭氧和温度探空廓线,结合NCEP/NCAR资料、TOMS臭氧总量卫星观测资料和NOAAHYSPLIT后向轨迹模式资料,通过个例分析探讨了影响青藏高原(下称高原)附近臭氧垂直分布的因子和过程。结果表明,动力过程是影响高原上空臭氧垂直分布的主要因子,特别是中高纬度高臭氧浓度的空气向南入侵会导致高原上空臭氧浓度的升高,影响高原上空臭氧低谷的范围大小和形态;尽管大气化学过程对高原上空的平流层下层臭氧垂直分布的影响并不显著,但是高原上空的平流层臭氧变化与温度变化具有较好的一致性。同时还发现,对流层上层的强反气旋系统,特别是中高纬度阻塞高压的边缘有明显的平流层空气向对流层入侵,从而导致对流层内臭氧浓度的增加。     

青藏高原周边对流层顶的时空分布、热力成因及动力效应分析

利用多套、多种再分析资料的逐日气候平均场,通过对比分析,揭示了青藏高原周边区域对流层顶分布及其季节演变的独特特征,并分析了其热力成因以及气候学效应。结果表明,与同纬度的落矶山和太平洋地区相比,青藏高原及伊朗高原区域对流层顶高度的冬夏变化幅度更大。冬季副热带对流层顶断裂带（热带对流层顶与极地对流层顶之间高度剧烈变化的过渡带）位于青藏与伊朗两个高原上空,春季开始两个高原上空对流层顶抬升迅速,夏季最高可超过热带对流层顶的高度（超过100 hPa）,成为同纬度甚至全球对流层顶最高点。青藏与伊朗两个高原上空对流层顶的剧烈抬高,对应两个高原上空大气气柱比同纬度明显偏暖,同时伴随着青藏与伊朗两个高原上空位势涡度值的明显降低。因此,在青藏与伊朗两个高原区域,由春至夏等熵面强烈下凹,同时等位涡面剧烈抬升;夏季时等位涡面及对流层顶断裂带在青藏高原北部成近乎上下垂直分布,与南北倾斜分布的等位温面接近正交分布。这种特征与夏季同纬度其他地区相对平缓的对流层顶断裂带、等位涡面以及等熵面的经向分布形成强烈对比。进一步研究发现,青藏与伊朗两个高原上空由春至夏迅速发展的强大热源是引起上述对流层顶变化特征的主要原因。不同的是,青藏高原上空主要由发展强烈的对流凝结潜热所主导,而伊朗高原上空则主要由绝热下沉加热引起;此外,由春季至夏季,随着青藏高原地区对流层顶与等熵面剧烈相交分布的形成,南亚高压也逐步控制青藏高原上空,在南亚高压东缘盛行的偏北气流作用下,中高纬度平流层的高位涡空气得以在青藏高原东缘及东亚地区沿剧烈倾斜的等熵面被输送到较低纬度的对流层。与降水的季节演变对比可知,平流层高位涡输送的出现、加强和减弱与夏季降水的发展、加强与减弱成同步对应关系。从而证实了青藏高原影响夏季东亚地区形成独特气候格局的事实,说明在这种影响过程中,平流层-对流层动力相互作用过程不可忽视。      

大气对流层平流层交换(STE)研究进展

大气平流层对流层交换(Stratosphere-Troposphere Exchange,STE)包括平流层向对流层的输送(Stratosphere-Troposphere Transport,STT)和对流层向平流层的输送(Troposphere-to-Stratosphere Transport,TST)2个过程,通常统称为STE交换过程.其对大气的辐射平衡、化学成分具有重要影响.研究STE对于大气化学、气候变化、平流层对流层耦合模式的发展等领域意义重大.对国内外不同尺度STE的观测、模拟与诊断做了评述,讨论了各种尺度STE的机制,比较了不同诊断方法和模式的性能和特点.着重指出目前天气尺度STE的研究虽然比较充分,但在STE过程中,中小尺度混合、湍流混合等物理过程的机制、诊断以及模拟方法的研究还有待提高.中小尺度强对流引起的TST对对流层污染物向平流层的输送作用和影响越来越受到关注.在全球快速城市化的背景下,研究城市群高污染区域强对流天气引起的TST过程及其影响具有重要的科学意义.     

关于平流层异常影响对流层天气系统的研究进展

人们传统上认为大气平流层很少能对对流层产生重要影响,但是,最近几年的观测研究表明这种自上而下的影响是显著的和非常重要的,特别地,近几年关于北极涛动的研究极大推动了这一问题的研究进展。这方面的研究发现平流层异常可以对对流层天气系统产生重要影响,也就是冬季平流层北极涛动（AO）的负异常可以诱发中高纬度地区寒潮天气,而AO的正异常则导致中高纬度地区的温暖晴朗天气。由于观测分析表明平流层AO的异常信号总是领先对流层AO异常,一些学者甚至建议冬季北半球平流层的异常信号可以作为预报对流层天气变化的先行指标,并可以把对流层天气预报的时限提高到3个星期以上。综述这一领域在最近几年的研究进展、阐述平流层异常影响对流层天气系统的物理机制和总结各种不同的学术观点,并对将来研究中应注意的问题提出了建议。     

Forever transnational: The ambivalence of return and cross‐border activities of the Shan across the Thailand‐Myanmar border

Over the past two decades, northern Thailand has experienced a massive influx of Shan ethnic nationals from Myanmar migrating to escape economic hardship and political conflicts at home. Myanmar's recent reforms raise the question of whether these migrants will return. The paper brings together the context of current changes in Myanmar with migrants' prospects of return and the impact of large‐scale migration on homeland politics. On the one hand, the paper explores the possibility that Shan migrants could remain forever transnational, for many of them will most likely never return. On the other hand, it considers the perspective of Shan elites in Myanmar on the fact a large portion of young Shan now spend their adult lives living and working in Thailand. While out‐migration of young Shan threatens the social fabric of Shan community in Myanmar, Shan ethnonationalists strive across the Myanmar border to regain loyalty among the Shan migrant population in Thailand. By examining the two aspects, this paper attempts to shed light on the impact of transnational migration on both migrants and their home country.     

The scope of fisheries learning exchanges for conservation

Over the past decade, fisheries learning exchanges (FLEs), in which representatives from different fisher communities come together to share marine conservation challenges and solutions, have been produced by a range of non-government organizations (NGOs) and federal agencies. This paper presents an overview of the history and scope of FLEs. A literature review, questionnaire, expert workshop, and key informant interviews were conducted. A content analysis was performed of the key informant interviews using a grounded theory approach. This paper offers a formal definition of a FLE, describes different configurations of FLEs, discusses the utility, common objectives, and common outcomes of FLEs, and outlines a research agenda for future work on FLEs. Organizers have found FLEs to have four main utilities: 1) FLEs leverage peer-to-peer sharing so that participants open each other's horizons for improving fisheries and fishing 2) FLEs catalyze and speed change, 3) FLEs are good for sharing thoughts that are difficult to receive and accept, 4) FLEs facilitate involvement and commitment from relevant parties needed for change. The most commonly documented purposes of FLEs were related to marine reserves, fisheries management strategies, bycatch reduction, and alternative livelihoods to fishing. The most common objectives among the FLEs surveyed were to encourage action or behavior, to openly exchange ideas, and to introduce new technology. As a result of FLEs the common outcomes were that participants were inspired to make changes, new programs were implemented, relationships were built and connections made, and participants enhanced their understanding of marine management strategies.     

鲁迅与顾琅早期地质作品新论——《中国地质略论》与《中国矿产志》知识来源考

鲁迅在日本留学期间曾于1903年在《浙江潮》发表《中国地质略论》一文,1906年与同到日本留学的顾琅合作出版《中国矿产志》(附《中国矿产全图》)一书。它们在中国地质学史上均具有开创性并产生重要影响,特别是《中国矿产志》被认为是中国第一部地质矿产著作。本文从中日地质学交流的角度,结合新发现的史料,通过文本对比分析,指出《中国地质略论》和《中国矿产志》均是吸收当时日本的一些地学著作编写而成。《中国地质略论》的地史学内容主要来源于佐藤传藏《地质学》(1898)一书,有关煤炭内容以及中国煤田分布图则来自日本海军少将肝付兼行发表在《太阳》(1903)杂志上的《东方之煤源》一文;《中国矿产志》的导言部分是在《中国地质略论》的基础上拓展而成,增补的内容则参考了矢津昌永的《清国地志》(1905)、横山又次郎的《地质学教科书》(1903)以及石川成章的《地球发达史》(1904)等著作,本言部分主要参考了日本地质调查所1902年发表的《清国及韩国主要矿产颁布图说明——附清国主要矿产地名表》;《中国矿产全图》则是顾琅依据日本《清国主要矿产分布图》绘制而成。《中国地质略论》和《中国矿产志》(附《中国矿产全图》...     

Thermodynamic exchanges between the external boundary layer and the indoor microclimate at the Basilica of Santa Maria Maggiore, Rome, Italy: the problem of conservation of ancient works of art

The Basilica of Santa Maria Maggiore, Rome, is an example of how ancient buildings with thick walls lessen the impact of the external temperature and humidity variations. The external influence on the internal microclimate is studied in order to gather information on how the building exchanges heat and moisture. Correlations between outdoor and indoor values are found. The results are applied to the calculation of the condensation-evaporation cycles inside micropores due to the Kelvin effect, to assess their impact on works of arts placed inside and outside the Basilica. It was found that the building attenuation is not sufficient to avoid damage due to condensation-evaporation cycles on stones and plasters. Some suggestions are made in order to mitigate the temperature variations during the liturgical offices.     

Tidal sands as biogeochemical reactors

Sandy sediments of continental shelves and most beaches are often thought of as geochemical deserts because they are usually poor in organic matter and other reactive substances. The present study focuses on analyses of dissolved biogenic compounds of surface seawater and pore waters of Aquitanian coastal beach sediments. To quantitatively assess the biogeochemical reactions, we collected pore waters at low tide on tidal cross-shore transects unaffected by freshwater inputs. We recorded temperature, salinity, oxygen saturation state, and nutrient concentrations. These parameters were compared to the values recorded in the seawater entering the interstitial environment during floods. Cross-shore topography and position of piezometric level at low tide were obtained from kinematics GPS records. Residence time of pore waters was estimated by a tracer approach, using dissolved silica concentration and kinetics estimate of quartz dissolution with seawater. Kinetics parameters were based on dissolved silica concentration monitoring during 20-day incubations of sediment with seawater. We found that seawater that entered the sediment during flood tides remained up to seven tidal cycles within the interstitial environment. Oxygen saturation of seawater was close to 100%, whereas it was as low as 80% in pore waters. Concentrations of dissolved nutrients were higher in pore waters than in seawater. These results suggest that aerobic respiration occurred in the sands. We propose that mineralised organic matter originated from planktonic material that infiltrated the sediment with water during flood tides. Therefore, the sandy tidal sediment of the Aquitanian coast is a biogeochemical reactor that promotes or accelerates remineralisation of coastal pelagic primary production. Mass balance calculations suggest that this single process supplies about 37 kmol of nitrate and 1.9 kmol of dissolved inorganic phosphorus (DIP) to the 250-km long Aquitanian coast during each semi-diurnal tidal cycle. It represents about 1.5% of nitrate and 5% of DIP supplied by the nearest estuary.